JP5759825B2 - Filtration apparatus and filtration method - Google Patents

Description

  The present invention relates to a filtration apparatus and a filtration method for filtering a stock solution and taking out the filtrate, and in particular, a diatomaceous earth filtration device for filtering a stock solution by passing the stock solution through a filter element coated with a filter aid such as diatomaceous earth and a filtration method using the same. About.

  As a filtering device, a device is known in which a stock solution is filtered through a filter element coated with a filter aid such as diatomaceous earth (for example, Patent Document 1 below). Examples of the filter element include a candle type formed by winding a metal wire in a cylindrical shape and a leaf type formed of a wire mesh plate. The filter element is used in a casing of the filter body.

  As the filtration process proceeds, the internal pressure of the filter body increases due to an increase in filtration resistance, and finally the filtration limit is reached, so the supply of the stock solution is stopped. At this time, the residual liquid remaining inside the filter body can be recovered as a filtrate by air pressing. Air pushing is to push the residual liquid through high pressure compressed air and pass it through the filtration element.

  However, when filtering a stock solution with poor filterability, such as fresh soy sauce containing a large amount of highly viscous syrup or soy, it is difficult to air-press all the remaining liquid in the filter body. Even if it is a stock solution with good filterability, it takes time to recover all of the remaining liquid as a filtrate by pushing air. For this reason, Patent Document 1 proposes to collect the remaining liquid that cannot be filtered by air pressing without passing through the filter element.

JP 2009-148680 A

  The recovered residual liquid can be filtered as a stock solution in the next filtration step. However, when the residual liquid amount increases, the burden of the filtration process in the next filtration step increases. In addition, in the production plan, when time is required until the next filtration step, there is a problem such as decay of the remaining liquid, which is not hygienic. Furthermore, the type of the stock solution may change in the next filtration step, and the recovered residual solution may not be mixed with the stock solution in the next filtration step. In such a case, there is no choice but to provide a dedicated facility (residual liquid filter) for filtering the residual liquid, or to dispose of the residual liquid.

  For example, a cartridge filter or the like is used for the residual liquid filter. However, since the cartridge filter is disposable, the greater the amount of residual liquid, the more frequently the cartridge filter is replaced, and the cost required for the residual liquid filtration process increases. Therefore, it is desirable that the remaining liquid amount be as small as possible. The amount of residual liquid increases as the capacity of the filter main body that has been filtered at the end of the filtration process increases. In the configuration having one filter main body as in the filtering device of Patent Document 1, the amount of residual liquid increases when the capacity of the filter main body is large. Moreover, since the filtration area to be used cannot be changed according to the processing amount of stock solution, it is inefficient.

  On the other hand, in the configuration in which the one filter main body is divided into a plurality of filter main bodies, and the total filtration area of the plurality of filter main bodies corresponds to the one filter main body, Since the number of filter main bodies to be used, that is, the filtration area to be used can be selected according to the throughput, it is efficient. However, if a plurality of filter main bodies are selected, a residual liquid corresponding to the capacity of the plurality of filter main bodies is generated, so that the residual liquid amount increases.

  The present invention solves the conventional problems as described above, and an object of the present invention is to provide a filtration apparatus and a filtration method capable of reducing the amount of residual liquid even when a plurality of filter bodies are used.

  In order to achieve the above object, a filtration device of the present invention is a filtration device that filters a stock solution to take out the filtrate, and is connected to each of the filter bodies to filter a plurality of filter bodies that filter the stock solution. The flow state of the filtered liquid discharge flow path for taking out the liquid, the remaining liquid collecting flow path connected to each filter body for collecting the remaining liquid remaining in each filter body, and the flow state of the residual liquid collecting flow path are switched. A flow path changing mechanism is provided, and the stock solution is simultaneously filtered by two or more filter bodies, and the residual liquid recovery flow is switched to the state in which the residual liquid recovery flow path is circulated by the flow path changing mechanism. The residual liquid collected through the passage is filtered by a filter main body different from the collection source filter main body.

  The filtration method of the present invention is a filtration method for removing a filtrate by filtering the stock solution, and using a plurality of filter bodies for filtering the stock solution, and a filtrate discharge channel for taking out the filtrate into each of the filter bodies. And a residual liquid recovery flow path for recovering the residual liquid remaining in each filter body, and the stock solution is simultaneously filtered by two or more filter main bodies to determine the flow state of the residual liquid recovery flow path. Switching to a state in which the residual liquid recovery flow path is in circulation by the switching flow path changing mechanism, and filtering the residual liquid recovered through the residual liquid recovery flow path with a filter body different from the recovery filter main body. It is characterized by doing.

  According to the present invention, the residual liquid of the filter main body does not remain as a residual liquid, but is filtered by a filter main body different from the collection source filter main body. Therefore, even when a plurality of filter bodies are used, the residual liquid at the end of the filtration process can be suppressed to only the residual liquid in the filter body that is finally recovered as a residual liquid, and the amount of residual liquid is reduced. be able to. Furthermore, since the stock solution is simultaneously filtered by two or more filter bodies, the time required for filtration can be suppressed.

  Here, the residual liquid remaining in the filter body when the filtration limit is reached can also be taken out as a filtrate by air pressing which is filtered off by high-pressure compressed air. In the present invention, the residual liquid can be filtered with another filter body as described above. For this reason, the present invention is particularly suitable when the stock solution is difficult to filter and it is difficult to filter all the remaining liquid by air pressing, or when it takes time to collect all the remaining liquid by air pressing. validate.

  In the filtering device of the present invention, it is preferable that a control mechanism for shifting the timing of switching the flow state of the residual liquid recovery flow path by the flow path changing mechanism is provided between the plurality of filter bodies. In the filtration method of the present invention, it is preferable that the timing of switching the flow state of the residual liquid recovery flow path is shifted between the plurality of filter bodies.

  In this configuration, even if the first filter body of the plurality of filter bodies shifts to the residual liquid recovery, the other filter bodies can maintain the filtration process. In this case, the remaining liquid of the first filter body can be filtered by another filter body. For example, when three or more filter main bodies are provided, the residual liquid recovered from the first filter main body is dispersed and filtered in the remaining two or more filter main bodies. Subsequently, the residual liquid collected from the second filter body is filtered by the remaining one or more filter bodies. In this filtration process, the amount of residual liquid carried over to the filter body that is finally recovered is the same as when the remaining liquid from other filter bodies is carried over to the filter body that is finally recovered. In comparison, it can be reduced. Thereby, the filtration area of the filter main body in which the residual liquid is finally recovered can be reduced, and as a result, the capacity of the filter main body in which the residual liquid is finally recovered can be reduced. As described above, in the present invention, the residual liquid at the end of the filtration step is only the residual liquid in the filter body that is finally recovered, so the capacity of the filter body that is finally recovered is reduced. As the amount of liquid remaining decreases.

  In the filtering device of the present invention, it is preferable that a pump for supplying a stock solution is connected to each filter body. In the filtration method of the present invention, it is preferable to connect a pump for supplying a stock solution to each filter body. According to this configuration, the stock solution can be supplied to each filter body with the pump dedicated to each filter body. For this reason, it becomes possible to use all the several filter main bodies with which a filtration apparatus is equipped, or to use the filter main body selected from the several filter main bodies. Further, by controlling the number of rotations of the motor of each pump, it becomes easy to individually set the flow rate of the stock solution supplied to each filter body.

  In the filtration device of the present invention, the plurality of filter bodies include a filter body having at least one of a filtration area and an internal volume different from that of other filter bodies, and is used according to the processing amount of the stock solution. It is preferable that the filter body to be selected can be selected. In the filtration method of the present invention, the plurality of filter bodies include a filter body that is different from other filter bodies in at least one of the filtration area and the internal volume, and is used according to the processing amount of the stock solution. It is preferable to select a filter body to be used. According to this configuration, even if the filtration area and internal volume required for each filtration process change according to the filtration conditions such as the processing amount of the stock solution and the filterability of the stock solution, the filter body can be selected freely can do. In the case of filtration using a filter aid, a change in the amount of filter aid used may also be mentioned as a change in filtration conditions.

  In the filtration apparatus of the present invention, it is preferable that the plurality of filter bodies are washed in order from the filter body from which the residual liquid is recovered. In the filtration method of the present invention, it is preferable that the plurality of filter bodies are washed in order from the filter body from which the residual liquid is recovered. According to this configuration, while the filter main body from which the residual liquid has been collected is being washed, the filtration process by the other filter main body is progressing. As a result, the time required for all processes is shortened. it can.

  In the filtering device of the present invention, a residual liquid filter for filtering residual liquid is provided separately from the plurality of filter main bodies, and the remaining number of filter main bodies is smaller than the number of filter main bodies used for the filtration. The liquid is preferably filtered with the residual liquid filter. In the filtration method of the present invention, a residual liquid filter for filtering the residual liquid is provided separately from the plurality of filter main bodies, and the residual liquid of the filter main body is smaller in number than the filter main bodies used for the filtration. It is preferable to filter with the residual liquid filter. According to this configuration, the entire stock solution can be taken out as a filtrate. For this reason, it is not necessary to carry over the remaining liquid to the next filtration process, and the burden of the filtration process in the next filtration process is not added. Further, as described above, in the present invention, the final residual liquid is limited to only the residual liquid in the filter main body that collects the residual liquid last. For this reason, the filtration burden of the residual liquid filter can be reduced, and the working time of residual liquid filtration can be shortened. Further, by reducing the filtration burden, for example, when a cartridge filter is used for the residual liquid filter, the replacement frequency is reduced and the cost required for the residual liquid filtration process can be reduced.

  According to the present invention, the residual liquid of the filter body is filtered by a filter body that is different from the collection source filter body, and even if a plurality of filter bodies are used, The residual liquid at the end of the treatment can be suppressed to only the residual liquid in the filter body that is finally recovered as the residual liquid, and the residual liquid amount can be reduced.

  For this reason, the present invention is particularly suitable when the stock solution is difficult to filter and it is difficult to filter all the remaining liquid by air pressing, or when it takes time to collect all the remaining liquid by air pressing. validate. Furthermore, since the stock solution is simultaneously filtered by two or more filter bodies, the time required for filtration can be suppressed.

The block diagram explaining the precoat process of the filtration apparatus which concerns on one Embodiment of this invention. The block diagram explaining the filtration process of the filtration apparatus which concerns on one Embodiment of this invention. The block diagram explaining the residual liquid collection process (1) of the filtration apparatus which concerns on one Embodiment of this invention. The block diagram explaining the residual liquid collection process (2) of the filtration apparatus which concerns on one Embodiment of this invention. The block diagram explaining the residual liquid collection process (3) of the filtration apparatus which concerns on one Embodiment of this invention. The block diagram explaining the residual liquid transfer process of the filtration apparatus which concerns on one Embodiment of this invention. The block diagram explaining the residual-liquid filtration process of the filtration apparatus which concerns on one Embodiment of this invention. The block diagram explaining the washing | cleaning process of the filtration apparatus which concerns on one Embodiment of this invention.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a configuration diagram of a filtration device 10 according to an embodiment of the present invention. This figure is also a block diagram for explaining a pre-coating process described later. First, a schematic configuration of the filtration device 10 will be described with reference to FIG. The filter device 10 is a diatomaceous earth filter device. The diatomaceous earth filtration device is a device that clarifies the stock solution by passing the stock solution through a filter element coated with a filter aid (diatomaceous earth, cellulose, activated carbon, etc.).

  Three filter bodies 1 to 3 are connected to the stock solution tank 20 in parallel via a flow path constituted by piping. The stock solution tank 20 is supplied with a stock solution to be filtered. When all of the three filter bodies 1 to 3 are used, the stock solution in the stock solution tank 20 is supplied to the filter bodies 1 to 3. The stock solution is filtered by passing through the filter elements 7 to 9 built in the filter main bodies 1 to 3, and the filtrate is taken out from the filter main bodies 1 to 3.

  The filter body 1 includes a plurality of filter elements 7 in a cylindrical casing 4. Similarly, the filter main body 2 and the filter main body 3 incorporate a plurality of filter elements 8 and a plurality of filter elements 9 in a casing 5 and a casing 6, respectively. The filter elements 7 to 9 are illustrated in a candle type example, and are formed by winding a metal wire in a cylindrical shape. At the time of filtration, a precoat layer is formed on the surfaces of the filtration elements 7 to 9 by the filter aid.

  The undiluted | stock solution supplied from the supply ports 40-42 in the filter main bodies 1-3 passes the precoat layer formed in the surface of the filtration elements 7-9, is filtered, and becomes a filtrate. This filtrate passes through the gaps between the metal wires of the filter elements 7 to 9 and flows into the filter elements 7 to 9 and is discharged from the discharge ports 43 to 45. These discharged filtrates are collected in the filtrate tank 50.

  The filter elements 7 to 9 can be of various specifications, and are not limited to a cylindrical one, but may be formed of a wire mesh flat plate, not limited to a metal filter, and may be a resin or cloth. Or a filter such as paper. Further, in FIG. 1, the filtration elements 7 to 9 are candle hanging types suspended inside the casings 4 to 6, but may be a candle standing type in which the filtration elements 7 to 9 are erected from the bottom up. .

  Hereinafter, the filtration process of the stock solution by the filtration device 10 will be described in the order of steps. First, among the three filter bodies 1 to 3, the number of filter bodies to be used is selected according to the processing amount of the stock solution. The following description is a case where all three filter bodies 1 to 3 are used. FIG. 1 is a configuration diagram illustrating a precoat process. The flow path shown by the thick line in FIG. 1 indicates the flow of the liquid in the precoat process. In the precoat process, a filter aid is added to the stock solution supplied to the stock solution tank 20 and the stock solution tank 20 and the filter main bodies 1 to 3 are circulated, so that a precoat layer with a filter aid is applied to the surfaces of the filter elements 7 to 9. Is formed.

  With reference to FIG. 1, the flow path circulating in the precoat process will be described. The stock solution tank 20 and the filter body 1 are connected by a stock solution supply flow path 11, the stock solution tank 20 and the filter body 2 are connected by a stock solution supply flow path 12, and the stock solution tank 20 and the filter body 3 are connected by a stock solution supply flow path 13. Connected with. A pump 17 and a valve 14 are interposed in the stock solution supply flow path 11, a pump 18 and a valve 15 are interposed in the stock solution supply flow path 12, and a pump 19 and a valve 16 are interposed in the stock solution supply flow path 13.

  Further, the filter body 1 is connected to a precoat liquid circulation passage 21 in which a valve 24 is interposed. Similarly, the filter body 2 is connected to a precoat liquid circulation channel 22 with a valve 25 interposed therebetween, and the filter body 3 is connected to a precoat liquid circulation channel 23 with a valve 26 interposed.

  Furthermore, the filter main body 1 is connected to a filtrate discharge flow path 31 with a valve 34 interposed. Similarly, the filter body 2 is connected to a filtrate discharge flow path 32 with a valve 35 interposed therebetween, and the filter body 3 is connected to a filtrate discharge flow path 33 with a valve 36 interposed. The filtrate discharge flow paths 31 to 33 are flow paths for taking out the filtrate obtained in the filter main bodies 1 to 3.

  In the above-described flow path configuration, the flow path changing mechanism can be switched between a state where each flow path is in circulation and a state where the flow paths are not in circulation. In the present embodiment, the flow path changing mechanism is each valve interposed in each flow path. The flow state is not limited to the above-described flow path, and other flow paths to be described later are switched by the valves that are flow path changing mechanisms. Taking the filter main body 1 as an example, by opening the valve 24 and closing the valve 34, the precoat liquid circulation passage 21 is in a circulation state and the filtrate discharge passage 31 is not in a circulation state.

  In the precoat process, the valves 14 to 16 and the valves 24 to 26 are open, and the other valves are closed. That is, the stock solution supply channels 11 to 13 and the precoat solution circulation channels 21 to 23 indicated by thick lines in FIG. 1 are in a circulation state. In this distribution state, taking the filter main body 1 as an example, the stock solution from the stock solution tank 20 is supplied into the filter body 1 through the stock solution supply channel 11 by driving the pump 17. And it is discharged | emitted from the inside of the filter main body 1, and returns to the undiluted | stock solution tank 20 through the precoat liquid circulation flow path 21. FIG.

  In the precoat process, the filter aid is put into the stock solution tank 20 together with the stock solution, and the precoat solution in which the filter aid is suspended in the stock solution is supplied to the filter bodies 1 to 3. By circulating this precoat liquid, the filter aid is coated on the surfaces of the filter elements 7 to 9. When the precoat liquid is circulated for several tens of minutes, a precoat layer is formed on the surfaces of the filtration elements 7 to 9.

  When the precoat process is completed, the process proceeds to the filtration process. FIG. 2 is a configuration diagram illustrating the filtration process. In the filtration step, by opening the valves 34 to 36 that were closed in the precoat step and closing the valves 24 to 26, as shown by the thick lines in FIG. 2, the stock solution supply channels 11 to 13 and the filtrate discharge channel 31. ~ 33 will be in a distribution state.

  In this distribution state, the stock solutions from the stock solution tank 20 are supplied into the filter bodies 1 to 3 through the stock solution supply channels 11 to 13 by driving the pumps 17 to 19. In the precoat step, a precoat layer is formed on the surfaces of the filtration elements 7 to 9. Therefore, the undiluted | stock solution supplied in the filter main bodies 1-3 is filtered through a precoat layer, and turns into a clear filtrate. This filtrate flows into the inside of the filter elements 7 to 9 and is discharged from the discharge ports 43 to 45. The discharged filtrate passes through the filtrate discharge channels 31 to 33 and is collected in the filtrate tank 50.

  As the filtration process proceeds, impurities contained in the stock solution gradually adhere to the precoat layer. Along with this, the filtration resistance increases, the internal pressure of the casings 4 to 6 rises, and finally the filtration limit is reached. For this reason, when the internal pressure of the casings 4 to 6 rises to a certain value, the supply of the stock solution is stopped and the filtration is terminated.

  In the present embodiment, the filtration limit is reached in the order of the filter main body 1, the filter main body 2, and the filter main body 3, and the stock solution supply is stopped in this order. The unfiltered stock solution remaining in the filter body 1 when the stock solution supply to the filter body 1 is stopped is referred to as a residual liquid. The same applies to the filter body 2 and the filter body 3.

  The filter body 1 that has stopped supplying the stock solution then proceeds to a residual liquid recovery step. Thereafter, the process proceeds to the remaining liquid recovery step in the order of the filter body 2 and the filter body 3. Thus, in order to shift the transition time to the residual liquid recovery step, the filtration device 10 includes a control mechanism 30 (for example, a sequencer). In the present embodiment, the control mechanism 30 shifts the timing when the filtration limit is reached, and the timing of switching the flow state of the residual liquid recovery flow paths 51 to 53 by the valves that are flow path changing mechanisms is shifted. In FIG. 1 to FIG. 5 and FIG. 8, illustration of signal lines connecting the control mechanism 30 and each valve is omitted for easy viewing.

  Shifting the time of the filtration limit can be realized by making the stock solution supply amounts per unit filtration area to the filter main bodies 1 to 3 different from each other. The stock solution supply amount can be adjusted, for example, by providing an inverter for each of the pumps 17 to 19 and controlling the motor drive frequency of the pumps 17 to 19 by the control mechanism 30 to control the rotation speed of the motor. Hereinafter, the residual liquid recovery process for the filter body 1 is the residual liquid recovery process (1), the residual liquid recovery process for the filter body 2 is the residual liquid recovery process (2), and the residual liquid recovery process is for the filter body 3 Is called the residual liquid recovery step (3).

  FIG. 3 is a configuration diagram illustrating the remaining liquid recovery step (1). The thick line in FIG. 3 shows the flow path through which the liquid flows in the residual liquid recovery step (1). When the internal pressure of the casing 4 rises to a certain value, the pump 17 is stopped, the valve 14 is closed, and the supply of the stock solution to the filter body 1 is stopped. At the same time, the valve 57 is opened, and high-pressure compressed air that has passed through the compressed air supply channel 47 is supplied from the compressed air supply source 27 to the filter body 1. As a result, the residual liquid in the filter body 1 is pushed out from the supply port 40, and the filtrate in the filter body 1 is pushed out from the discharge port 43. Hereinafter, extruding residual liquid or filtrate from the filter main bodies 1 to 3 by supplying high-pressure compressed air is referred to as air pushing.

  A part of the remaining liquid passes through the filter element 7 and is filtered, and is pushed out from the discharge port 43 as a filtrate. In FIG. 3, since the valve 34 remains open, the filtrate pushed by air from the outlet 43 is collected in the filtrate tank 50 via the filtrate discharge passage 31.

  Most of the residual liquid in the filter main body 1 is pushed out as a raw liquid residual liquid that has not passed through the filter element 7 via the supply port 40. In FIG. 3, the valve 14 and the valve 64 are closed, the valve 54 is opened, and the residual liquid recovery flow path 51 is in a circulation state. For this reason, the residual liquid pushed out from the supply port 40 is recovered in the stock solution tank 20 via the residual liquid recovery flow path 51.

  While the residual liquid recovery step (1) of the filter main body 1 is in progress, the filtration steps in the filter main body 2 and the filter main body 3 are continued. Therefore, the residual liquid of the filter body 1 collected in the stock solution tank 20 is filtered by the filter body 2 and the filter body 3 and collected as a filtrate.

  FIG. 4 is a block diagram for explaining the residual liquid recovery step (2). The thick line in FIG. 4 indicates the flow path through which the liquid flows in the residual liquid recovery step (2). When the internal pressure of the casing 5 rises to a certain value, the pump 18 is stopped, the valve 15 is closed, and the supply of the stock solution to the filter body 2 is stopped. At the same time, the valve 58 is opened, and the compressed air that has passed through the compressed air supply channel 48 is supplied from the compressed air supply source 27 to the filter body 2. As a result, the residual liquid in the filter body 2 is pushed out from the supply port 41, and the filtrate in the filter body 2 is pushed out from the discharge port 44.

  A part of the remaining liquid passes through the filter element 8 and is filtered, and is extruded from the outlet 44 as a filtrate. In FIG. 4, since the valve 35 remains open, the filtrate that has been air-pressed from the discharge port 44 is collected in the filtrate tank 50 via the filtrate discharge passage 32.

  Most of the residual liquid in the filter body 5 is pushed out as a raw liquid residual liquid that has not passed through the filter element 8 via the supply port 41. In FIG. 4, the valve 15 and the valve 65 are closed, the valve 55 is opened, and the residual liquid recovery flow path 52 is in a circulation state. For this reason, the residual liquid pushed out from the supply port 41 is recovered in the stock solution tank 20 via the residual liquid recovery flow path 52.

  On the other hand, while the residual liquid recovery process (2) of the filter body 2 is in progress, the filtration process in the filter body 3 is continued. Therefore, the residual liquid of the filter body 2 collected in the stock solution tank 20 is filtered by the filter body 3 and collected as a filtrate.

  FIG. 5 is a block diagram for explaining the residual liquid recovery step (3). The thick line in FIG. 5 indicates the flow path through which the liquid flows in the residual liquid recovery step (3). When the internal pressure of the casing 6 rises to a certain value, the pump 19 is stopped, the valve 16 is closed, and the supply of the stock solution to the filter body 3 is stopped. At the same time, the valve 59 is opened, and the compressed air that has passed through the compressed air supply channel 49 is supplied from the compressed air supply source 27 to the filter body 3. As a result, the residual liquid in the filter body 3 is pushed out from the supply port 42, and the filtrate in the filter body 3 is pushed out from the discharge port 45.

  A part of the residual liquid passes through the filter element 9 and is filtered, and is pushed out from the discharge port 45 as a filtrate. In FIG. 5, since the valve 36 remains open, the filtrate that has been pushed by air from the discharge port 45 is collected in the filtrate tank 50 via the filtrate discharge passage 33.

  Most of the residual liquid in the filter body 3 is pushed out as a residual liquid in a raw liquid state not passing through the filter element 9 via the supply port 42. In FIG. 5, the valve 16 and the valve 66 are closed, the valve 56 is opened, and the residual liquid recovery flow path 53 is in a circulation state. For this reason, the residual liquid pushed out from the supply port 42 is recovered in the stock solution tank 20 via the residual liquid recovery flow path 53.

  In this embodiment, the residual liquid of the filter main body 1 collected in the stock solution tank 20 from the supply port 40 is filtered by the filter main body 2 and the filter main body 3 and collected as a filtrate. Moreover, the residual liquid of the filter main body 2 collected by the stock solution tank 20 from the supply port 41 is filtered by the filter main body 3, and is collect | recovered as a filtrate. That is, the residual liquid of the filter main body 1 and the filter main body 2 does not remain as an unfiltered stock solution, but is filtered by a filter main body different from the collection source filter main body. Therefore, even if the three filter main bodies 1 to 3 are used, the residual liquid at the end of the filtration process can be suppressed to only the residual liquid in the filter main body 3 that finally moves to the residual liquid recovery process. Can be reduced.

  In the present embodiment, a part of the residual liquid of the filter main body 1 and the filter main body 2 is collected by being filtered through the filter element 7 and the filter element 8 by air pressing. On the other hand, when filtering a difficult-to-filter undiluted solution having poor filterability, it is difficult to filter all residual liquid in the filter body by air pressing. Even if it is a stock solution with good filterability, it takes time to filter all the remaining liquid. In this embodiment, most of the residual liquid is collected in the stock solution tank 20 without passing through the filter element 7 and the filter element 8 when the air is pushed, and as described above, the filter body is different from the filter body of the collection source. Filtered. For this reason, in this embodiment, when the undiluted solution is difficult to filter and it is difficult to filter all the remaining liquid by air pressing, or when it takes time to collect all the remaining liquid by filtering by air pressing. Especially effective.

  Moreover, in this embodiment, since the undiluted | stock solution is simultaneously filtered with the three filter main bodies 1-3 in a filtration process, the time which filtration requires can be suppressed. Further, by simultaneously using the filter main bodies 1 to 3, the precoat process of FIG. 1 can be completed for three of the filter main bodies 1 to 3 at a time. This eliminates the need for a subsequent pre-coating process, shortens the time required for all processes, and simplifies switching of the flow path between processes.

  Furthermore, in this embodiment, the timing at which the flow path is switched from the filtration process to the residual liquid recovery process is shifted between the three filter bodies 1 to 3. For this reason, as above-mentioned, even if the filter main body 1 transfers to a residual liquid collection process (1), the filter main body 2 and the filter main body 3 can maintain a filtration process. In this case, the residual liquid of the filter body 1 is dispersed and filtered in the filter body 2 and the filter body 3. Subsequently, the residual liquid collected from the filter body 2 is filtered by the filter body 3. In this filtration process, the amount of residual liquid carried over to the filter main body 3 can be reduced as compared with the case where all the residual liquid of the filter main body 1 and the filter main body 2 is carried over to the filter main body 3 at one time. . Thereby, the filtration area of the filter main body 3 finally collected with the residual liquid can be reduced, and as a result, the capacity of the filter main body 3 can be reduced. As described above, in the present embodiment, the residual liquid at the end of the filtration step is only the residual liquid in the filter main body 3 that is finally recovered, so that the residual liquid becomes smaller as the capacity of the filter main body 3 is reduced. The amount is also reduced.

  In this embodiment, since the filter main bodies 1-3 are each provided with the pump 17, the pump 18, and the pump 19, the stock solution supply amount to the filter main bodies 1-3 can be varied. Thereby, the timing when the filter main bodies 1 to 3 reach the filtration limit, that is, the timing of switching the flow path from the filtration step to the residual liquid recovery step can be shifted. Adjustment of the stock solution supply amount to the filter main bodies 1 to 3 can be performed by controlling the motor rotation speed of the pumps 17 to 19 as described above, for example.

  Moreover, in this embodiment, since the three filter main bodies 1-3 are provided, it becomes possible to select the filter main bodies 1-3 to be used according to the processing amount of the stock solution.

  The remaining liquid collecting step (3) has been described above. When the remaining liquid collecting step (3) is completed, the remaining liquid collected in the remaining liquid collecting step (3) remains in the stock solution tank 20. The residual liquid may be filtered in the next filtration process, or may be filtered before the next filtration process is performed after adding a filtration facility. Hereinafter, filtration of the remaining liquid remaining in the stock solution tank 20 will be described.

  FIG. 6 is a block diagram for explaining the residual liquid transfer step, and FIG. 7 is a block diagram for explaining the residual liquid filtration step. 6 and 7 have the same configuration, the thick line in FIG. 6 indicates a flow path through which the liquid flows in the residual liquid transfer process, and the thick line in FIG. 7 indicates a flow path through which the liquid flows in the residual liquid filtration process. In FIG.6 and FIG.7, the equipment for residual liquid filtration is added to the filtration apparatus 10 shown to FIGS. FIGS. 6 and 7 mainly illustrate this additional equipment, and the portions not shown in FIGS. 6 and 7 have the same configuration as FIGS.

  With reference to FIG. 6, the equipment added for residual liquid filtration will be described. The stock solution supply channel 13 and the residual solution recovery tank 70 are connected by a residual solution transfer channel 86 with a valve 87 interposed therebetween. The residual liquid recovery tank 70 and the residual liquid filter 90 are connected by a residual liquid supply flow path 88 with a pump 89 and a valve 93 interposed therebetween. The residual liquid filter 90 includes a filtration filter 92 in the casing 91, and the residual liquid that has passed through the filtration filter 92 is recovered as a filtrate. The residual liquid filter 90 and the filtrate tank 50 are connected by a filtrate supply flow path 94.

  In the above configuration, in the residual liquid transfer step of FIG. 6, the valve 16 is closed, the valve 87 is opened, and the pump 19 is in operation. As a result, the residual liquid in the raw liquid tank 20 of FIG. 5 is recovered in the residual liquid recovery tank 70 via the raw liquid supply flow path 13 and the residual liquid transfer flow path 86. In the residual liquid filtration step of FIG. 7, the valve 93 is opened and the pump 89 is operating. As a result, the residual liquid in the residual liquid recovery tank 70 is filtered by the residual liquid filter 90 and is recovered in the filtrate tank 50 via the filtrate discharge flow path 94.

  By passing through the residual liquid transfer step of FIG. 6 and the residual liquid filtration step of FIG. 7, all of the stock solution can be taken out as a filtrate. For this reason, it is not necessary to carry over the remaining liquid to the next filtration process, and the burden of the filtration process in the next filtration process is not added. Further, as described above, in the present embodiment, the final residual liquid is limited to only the residual liquid in the filter main body 3 that finally moves to the residual liquid recovery step. For this reason, the filtration burden of the residual liquid filter 90 can be reduced, and the working time of residual liquid filtration can be shortened. Further, by reducing the filtration burden, for example, when a cartridge filter is used for the residual liquid filter 90, the replacement frequency is reduced and the cost required for the residual liquid filtration process can be reduced.

  Moreover, the residual liquid filtered with the residual liquid filter 90 is not restricted to the residual liquid of one filter main body. Finally, even if there are multiple filter bodies that move to the residual liquid recovery process, if this number is less than the filter body used at the beginning of the filtration process, the final residual liquid volume is used at the beginning of the filtration process. The amount of residual liquid for the filter body can be reduced. Therefore, even in this case, the filtration load of the residual liquid filter 90 can be reduced, and the cost reduction effect can be obtained by shortening the working time of the residual liquid filtration and reducing the replacement frequency of the residual liquid filter.

  Next, the cleaning process will be described. In the description with reference to FIGS. 1 to 7, the description of the cleaning process is omitted, but when the residual liquid recovery process (1) of the filter body 1 is completed, the process can be shifted to the cleaning process of the filter body 1. Similarly, when the residual liquid recovery process (2) is completed, the process can be shifted to the filter body 2 cleaning process, and when the residual liquid recovery process (3) is completed, the process is shifted to the filter body 3 cleaning process. Can do.

  FIG. 8 is a configuration diagram illustrating a cleaning process. The thick line in FIG. 8 shows the flow path through which the liquid flows when the filter main body 1 is in the cleaning process. In FIG. 8, the filter main body 1 has shifted to the cleaning process, but the filtration processes of the filter main body 2 and the filter main body 3 are continued. Valves 24 and 34 are closed and valve 74 is open. Therefore, the cleaning liquid from the cleaning liquid supply source 28 is discharged from the discharge port 43 into the filter main body 1 through the cleaning liquid supply channel 83. Since this cleaning liquid flows from the back surface side to the front surface side of the filter element 7, the filter aid forming the precoat layer on the surface of the filter element 7 is peeled off by this flow.

  In the flow path on the supply port 40 side of the filter main body 1, the valve 14 and the valve 54 are closed, the valve 64 is opened, and the drainage flow path 61 is in a circulation state. Therefore, the separated filter aid is collected in the drain tank 60 through the drain channel 61 together with the cleaning liquid.

  Although the cleaning process of the filter body 1 has been described above, the cleaning process of the filter body 2 and the filter body 3 is the same as that of the filter body 1. For this reason, about the washing | cleaning process of the filter main body 2 and the filter main body 3, detailed description is abbreviate | omitted and it demonstrates easily. The valve 75 and the valve 76 correspond to the valve 74, and the cleaning liquid supply channel 84 and the cleaning liquid supply channel 85 correspond to the cleaning liquid supply channel 83.

  When the residual liquid recovery step (2) is completed, the filter main body 2 moves to the cleaning step, and the cleaning liquid is discharged into the filter main body 2. The filter aid separated from the filter element 8 is collected in the drain tank 60 through the drain channel 62 together with the cleaning liquid. Similarly, when the residual liquid recovery step (3) is completed, the filter main body 3 moves to the cleaning step, and the cleaning liquid is discharged into the filter main body 3. The filter aid peeled off from the filter element 9 is collected in the drain tank 60 through the drain channel 63 together with the cleaning liquid.

  In the above embodiment, while the filter body 1 from which the residual liquid has been collected is being washed, the filtration process by the other filter body 2 and the filter body 3 is in progress. The time required for all processes can be shortened.

  Although this embodiment is an example which uses the three filter main bodies 1-3 of the filtration apparatus 10 simultaneously, you may use simultaneously two filter main bodies selected according to the throughput of the undiluted | stock solution. Further, the number of filter bodies included in the filter device may be two, or four or more. Furthermore, although the filtration apparatus 10 was demonstrated with the example of the candle-type diatomaceous earth filtration apparatus, another kind of filtration apparatus may be sufficient. For example, a leaf type diatomaceous earth filtration device may be used, or a filtration device that does not use diatomaceous earth.

  Hereinafter, the present embodiment will be described more specifically with reference to examples. An Example is the structure similar to the filtration apparatus 10 shown in FIG. 1, and a stock solution is filtered through each process demonstrated using FIGS. Further, in the embodiment, the residual liquid transfer process of FIG. 6, the residual liquid filtration process and the cleaning process of FIG. 7 are also executed.

The filter body 1 and the filter body 2 have the same specifications, the filtration area is 4 m ² , and the internal volume is 400L. Casing 4 and casing 5 were made of stainless steel. The filter element 7 and the filter element 8 were each 19 pieces, and it was set as the candle type filter made from stainless steel of diameter 60mm and length 1200mm. The filter body 3 has a filtration area of 1 m ² and an internal volume of 100 L. The casing 6 has a cylindrical shape made of stainless steel. The number of the filter elements 9 was eight, and a stainless steel candle type filter having a diameter of 60 mm and a length of 700 mm was used.

Residual liquid filtration apparatus 90 of FIG. 6, the housing 91 of stainless steel cylindrical, and to those internal diameter 170 mm, a length of 800mm pouch-like bag filter 9 2 one. As the stock solution, 20 kL of a hard-to-filter sugar solution was used.

  In the pre-coating process of FIG. 1, a stock sugar solution was introduced into the stock solution tank 20 and 13.5 kg of diatomaceous earth used for pre-coating was introduced. After stirring these well, a precoat solution in which diatomaceous earth was suspended in the stock solution was simultaneously supplied to the casings 4 to 6 by pumps 17 to 19. The flow rate of the precoat liquid at this time was set to 200 L / min for the filter main body 1 and the filter main body 2, and 50 L / min for the filter main body 3. Several tens of minutes after the circulation of the precoat liquid was started, it was confirmed that the surface of the filter elements 7 to 9 was precoated with diatomaceous earth and the precoat liquid returned to the stock solution tank 20 was clarified.

  After confirming that the pre-coating process was completed, the valves 34 to 36 were opened, and then the valves 24 to 26 were closed, and the process proceeds to the filtration process of FIG. The standard of the flow rate of the filtrate discharged | emitted from the filter main bodies 1-3 at this time was 160 L / min for the filter main body 1, 120 L / min for the filter main body 2, and 25 L / min for the filter main body 3. As the filtration process proceeds, impurities contained in the sugar liquid adhere to the precoat layers formed on the surfaces of the filtration elements 7 to 9, and the discharge amount of the filtrate gradually decreases. For this reason, in the Example, it filtered so that the frequency of the pumps 17-19 might be controlled so that it might become the said flow volume, and when the internal pressure of the casings 4-6 reached to 400 kPa, it set so that a residual liquid collection process might be started.

  Sixty minutes after the start of the filtration step, the internal pressure of the casing 4 reached 400 kPa, and the process shifted to the residual liquid recovery step (1) in FIG. At this time, the pump 17 was stopped and the valve 14 was closed. At the same time, the valve 57 was opened and 450 kPa of compressed air was supplied into the casing 4 from the compressed air supply source 27 through the compressed air supply flow path 47, and the valve 54 was further opened. A part of the residual liquid inside the casing 4 passes through the filter element 7 and is collected as a filtrate into the filtrate tank 50 through the filtrate waste flow path 31. Was collected in the stock solution tank 20. Further, the collected residual liquid of the filter main body 1 was mixed with the raw liquid in the raw liquid tank 20 and filtered by the filter main body 2 and the filter main body 3.

  After 80 minutes from the start of the filtration process, the internal pressure of the casing 5 reached 400 kPa, and the process shifted to the residual liquid recovery process (2) in FIG. At this time, the pump 18 was stopped and the valve 15 was closed. At the same time, the valve 58 was opened, 450 kPa of compressed air was supplied into the casing 5 from the compressed air supply source 27 via the compressed air supply channel 48, and the valve 55 was opened. A part of the residual liquid inside the casing 5 passes through the filter element 8 and is recovered in the filtrate tank 50 through the filtrate discharge flow path 32, but most of the residual liquid passes through the residual liquid recovery flow path 52. It was collected in the stock solution tank 20. Further, the collected residual liquid of the filter body 2 was mixed with the stock solution in the stock solution tank 20 and filtered by the filter body 3.

  After 100 minutes from the start of the filtration process, the internal pressure of the casing 6 reached 400 kPa, and the process shifted to the residual liquid recovery process (3) in FIG. At this time, the pump 19 was stopped and the valve 16 was closed. At the same time, the valve 59 was opened, 450 kPa of compressed air was supplied into the casing 6 from the compressed air supply source 27 through the compressed air supply flow path 49, and the valve 56 was opened. A part of the residual liquid inside the casing 6 passes through the filter element 9 and is collected in the filtrate tank 50 via the filtrate discharge flow path 33, but most of the residual liquid passes through the residual liquid collection flow path 53. It was collected in the stock solution tank 20.

  Subsequently, the process proceeds to the residual liquid transfer process of FIG. 6, and the residual liquid of the filter body 3 recovered in the raw liquid tank 20 in the residual liquid recovery process (3) is transferred to the residual liquid recovery tank 70 of FIG. It was done. At this time, the amount of residual liquid transferred was 90 L. When the transfer of the residual liquid was completed, the process shifted to the residual liquid filtration step of FIG. The residual liquid in the residual liquid recovery tank 70 was filtered by a residual liquid filter 90 and recovered in the filtrate tank 50. The standard of the filtration flow rate at this time was 10 L / min. Also in the residual liquid filtration step, the amount of filtrate discharged gradually decreased as filtration progressed, but 90 L of the residual liquid could be filtered in 30 minutes from the start of the residual liquid filtration step. In the residual liquid filtration step, the final internal pressure of the housing was 150 kPa.

  In the example, the same cleaning process as in the above embodiment was performed. The filter body 1 that has finished the residual liquid recovery step (1) in FIG. 3 has shifted to the cleaning step in FIG. Hot water at 60 ° C. was used as the cleaning liquid. The warm water was released into the filter main body 1 from the discharge port 43 through the cleaning liquid supply channel 83 by opening the valve 74. After repeating this warm water discharge 3 times, when the inside of the filter main body 1 was visually confirmed, it was confirmed that all of the diatomaceous earth adhering to the surface of the filter element 7 was peeled off. The same washing was performed on the filter main body 2 after the residual liquid recovery step (2) in FIG. 4 was performed, and was performed on the filter main body 3 after the residual liquid recovery step (3) in FIG. It was confirmed that all of the diatomaceous earth adhered to the surface of the filter element 8 of the filter main body 2 and the filter element 9 of the filter main body 3 were peeled off.

As described above, in the present embodiment, the filtration area of the filter body 1 and the filter body 2 is 4 m ² and the internal volume is 400 L, and the filtration area of the filter body 3 is 1 m ² and the internal volume is 100 L. In this case, the total filtration area is 9 m ² and the total capacity is 900L. In this configuration, in this example, the final residual liquid amount was 90 L as described above. On the other hand, the operation of Comparative Example 1 was performed in which the number of filter main bodies was one, the filter area of the filter main body was 9 m ² , and the internal volume was 850 L. In Comparative Example 1, the residual liquid amount was 780 L. Furthermore, using the filter main bodies 1 to 3 of this example, the residual liquid recovery steps (1) to (3) were omitted, and the operation of Comparative Example 2 was performed to take out the filtrate from each of the filter main bodies 1 to 3. . Comparative Example 2 is a configuration in which the filter main body of Comparative Example 1 is divided into three filter main bodies. The total filtration area 9 m ² of the three filter main bodies of Comparative Example ² is the same as that of the filter main body of Comparative Example 1. The filtration area is the same as 9 m ² . In Comparative Example 2, the residual liquid amount of the filter main body 1 and the filter main body 2 was 370 L, the residual liquid amount of the filter main body 3 was 90 L, and the total residual liquid amount was 830 L.

  As described above, in this example, although the total filtration area was the same as that of Comparative Example 1 and Comparative Example 2, the amount of residual liquid could be greatly reduced as compared with Comparative Example 1 and Comparative Example 2. Thus, it can be seen that the embodiment can reduce the filtration burden of the residual liquid filter 90 and can reduce the work time required for the residual liquid filtration as compared with Comparative Examples 1 and 2.

1, 2, 3 Filter body 11, 12, 13 Stock solution supply flow path 17, 18, 19 Pump 20 Stock solution tank 30 Control mechanism 31, 32, 33 Filtrate discharge flow path 47, 48, 49 Compressed air supply flow path 51 , 52, 53 Residual liquid recovery flow path 54, 55, 56 Valve (flow path changing mechanism)
60 Drain tank 61, 62, 63 Drain flow path 70 Residual liquid recovery tank 83, 84, 85 Cleaning liquid supply flow path 90 Residual liquid filter

Claims (12)

A filtration device for filtering a stock solution and taking out the filtrate,
A plurality of filter bodies for filtering the stock solution;
A filtrate discharge passage connected to each filter body to take out the filtrate;
A residual liquid collection flow path for collecting the residual liquid that is connected to each filter body and remains inside each filter body;
A flow path changing mechanism for switching the flow state of the residual liquid recovery flow path,
The stock solution is filtered simultaneously by two or more filter bodies,
In the two or more filter bodies, the stock solution supply is stopped in the order in which the filtration limit is reached,
For the filter main body in which the stock solution supply is stopped, the flow path changing mechanism is switched to the state in which the residual liquid recovery flow path is in circulation,
The residual liquid recovered through the residual liquid recovery flow path is filtered by the filter main body in which the filtration process different from the recovery filter main body is continued among the two or more filter main bodies. The filtration apparatus characterized by the above-mentioned.   The filtration device according to claim 1, further comprising a control mechanism for shifting a timing of switching the flow state of the residual liquid recovery flow path by the flow path changing mechanism between the plurality of filter bodies.   The filtration device according to claim 1 or 2, wherein a pump for supplying a stock solution is connected to each filter body.   The plurality of filter bodies include a filter body having at least one of a filtration area and an internal volume different from that of other filter bodies, and a filter body to be used can be selected according to the processing amount of the stock solution. The filtration device according to any one of claims 1 to 3.   The filtration device according to any one of claims 1 to 4, wherein the plurality of filter bodies are washed in order from the filter body from which the residual liquid is collected.   A residual liquid filter for filtering the residual liquid is provided separately from the plurality of filter main bodies, and the residual liquid of a smaller number of filter bodies than the filter main body used for filtration is filtered by the residual liquid filter. The filtration device according to any one of claims 1 to 5. A filtration method for removing a filtrate by filtering a stock solution,
Using multiple filter bodies that filter the stock solution,
Connected to each of the filter bodies is a filtrate discharge flow path for taking out the filtrate, and a residual liquid collection flow path for collecting the residual liquid remaining inside each of the filter bodies,
Filter the stock solution simultaneously with two or more filter bodies,
The two or more filter bodies stop the stock solution supply in the order in which the filtration limit is reached,
With respect to the filter main body that has stopped supplying the stock solution, the flow change mechanism that switches the flow state of the residual liquid recovery flow path is switched to the state in which the residual liquid recovery flow path is in circulation,
The residual liquid recovered through the residual liquid recovery flow path is filtered by a filter body in which the filtration process different from the recovery source filter body is continued among the two or more filter bodies. Filtration method.   The filtration method according to claim 7, wherein the timing of switching the flow state of the residual liquid recovery flow path is shifted between the plurality of filter main bodies.   The filtration method according to claim 7 or 8, wherein a pump for supplying a stock solution is connected to each filter body.   The filter main body is selected according to the processing amount of the stock solution by including a filter main body in which at least one of the filtration area or the internal volume is different from the other filter main bodies in the plurality of filter main bodies. The filtration method according to any one of 7 to 9.   The filtration method according to any one of claims 7 to 10, wherein the plurality of filter bodies are washed in order from the filter body from which the residual liquid is recovered. A residual liquid filter for filtering the residual liquid is provided separately from the plurality of filter main bodies, and the residual liquid of a smaller number of filter main bodies than the filter main body used for filtration is filtered by the residual liquid filter. Item 12. The filtration method according to any one of Items 7 to 11.

Images